CN112739462A - Metering system with metering substance cooling device - Google Patents

Abstract

The invention relates to a metering system (1) for metering a substance, comprising a metering device (5) having a housing (11) with at least one inlet channel (80) for metering the substance, a nozzle (40), a spray element (31) and an actuator unit (10) coupled to the spray element (31) and/or the nozzle (40). The metering device (5) also comprises a plurality of temperature control devices (2, 2 ') which are coupled to or integrated in the housing (11) and are each associated with different temperature zones (6, 6') of the metering system (1) in order to control the temperature of said temperature zones in a different manner. At least one first temperature zone (6) is associated with the metered-substance storage holder (70) and at least one second temperature zone (6') is associated with the nozzle (40). At least one of the temperature control devices, preferably at least the temperature control device (2) associated with the metered-substance storage holder (70), preferably comprises a cooling device (3, 3 ') having at least one cooling source (93, 93', 95, 99).

Description

Metering system with metering substance cooling device

Technical Field

The invention relates to a metering system for metering a substance, having a metering device comprising a housing and a metered substance reservoir holder (vortatsharterung) coupled to or integrated in the housing, the housing comprising an inlet channel for the metered substance, a nozzle, a spray element and an actuator unit coupled to the spray element and/or the nozzle. The invention also relates to a method for operating a metering system.

Background

Metering systems of the type mentioned at the outset are generally used for the targeted application of a medium to be metered to a target surface. In the context of the so-called "micro-metering technique", it is generally required for this purpose that a very small quantity of the metering substance is placed on the target surface precisely to the point and without contact, i.e. without contact between the metering system and the target surface. This contactless method is also commonly referred to as the "jetting method". Typical examples of this are the metering of glue dots, solder, etc. or the application of converter material for LEDs when assembling circuit boards or other electronic components.

The main requirement here is that the metered substances are delivered to the target surface with high precision, i.e. at the correct point in time, in the correct position and in precisely metered amounts. This can be achieved, for example, by outputting the metered substance in drops through a nozzle of the metering system. In this case, the medium is only in contact with the interior of the nozzle and the mostly front region of the spray element of the metering system. Here, a preferable method is to eject each droplet in the form of an "ink jet method" as also used in an ink jet printer. The size of the drops or the quantity of the medium per drop can be predetermined as precisely as possible by the configuration of the nozzle and the actuation of the nozzle and by the action of the nozzle achieved thereby. Alternatively, the metered substances can also be sprayed in the form of a spray.

For dispensing the medium from the metering system, a movable spray element, for example a tappet, can be arranged in a nozzle of the metering systemRod

The ejector element can be made to impact forward inside the nozzle at a relatively high speed in the direction of the nozzle opening or discharge opening, thereby causing a drop of the medium to be ejected and then pulled back again.

Alternatively or additionally, the nozzle of the metering system itself can be moved in the ejection direction or in the retraction direction. For the purpose of dispensing metered substances, the nozzle and the spray element arranged inside the nozzle can be moved toward one another or away from one another, wherein this relative movement can be effected exclusively by the movement of the outlet opening or the nozzle or at least partially also by a corresponding movement of the spray element.

In general, the spray element can also be brought into the closed state by fixedly attaching it in the nozzle to a sealing seat of the nozzle opening and temporarily retaining it there. Depending on the metered substance, however, the ejection element can also remain in the retracted state, i.e. away from the sealing seat, so that no media drops issue from the nozzle ("open jet method").

The movement of the jet member and/or the nozzle is usually effected by means of an actuator system of a metering system. Piezoelectric actuators are preferred especially in applications requiring high purity metrology resolution. The invention can be operated using all the usual actuator principles, i.e. hydraulically, pneumatically and/or electromagnetically operated actuators can also be used in metering systems.

In order to improve the processing properties of the metering substance and to achieve as high and constant a metering accuracy as possible at the metering substance output, the metering substance is generally heated to a processing temperature specific to the metering substance before it is ejected from the nozzle. In particular, metering substances with a medium or high viscosity are heated before processing, i.e. before ejection, so that the viscosity is reduced and the quality of the spraying process is improved, or can be achieved entirely within the permissible range of fluctuations in the mass of the metering substance. The metering substance having a lower viscosity can also have an advantageous effect on the long service life of the metering system, since the parts of the metering system which participate in the injection are used to a lesser extent. Metering substances with medium or high viscosity are, for example, adhesives, solders, casting compounds, thermally conductive pastes, oils, silicones, dyes, etc.

In most conventional metering systems, the metering substance is therefore heated in a targeted manner at least in the nozzle or in the nozzle chamber of the metering system.

Although it is possible to improve the metering accuracy of high-viscosity metering substances by heating the metering substance to the processing temperature, it has been found that this mode of operation has a significant influence on the processing time (pot life) of the metering substance. Pot life or use-life describes the period of time between the manufacture or provision of a preferably multicomponent metered substance and the termination of its processability. As the pot life is reached, the material properties of the metered substance change such that the metered substance can no longer be processed in the desired quality, i.e. is unusable. Depending on the chemical nature of the dosing substance, an increase in the temperature of the dosing substance can lead to a significant reduction in the pot life. This is problematic in particular when working thermally hardening metering substances, such as adhesives.

Heating the metering substance to the processing temperature in conventional metering systems leads to the metering substance reaching the end of its pot life before processing, i.e. before being ejected from the nozzle. For example, in the case of "total" heating of the metered substance in the nozzle, it can happen that the metered substance in the "waiting area" still before the nozzle, for example in the feed area and possibly even in the metered-substance reservoir, is heated by convection from the heated nozzle (simultaneously). This aspect can mean that the metered material that has become unusable must be recovered in advance or a new batch of metered material must be provided, with additional costs. On the other hand, more serious consequences can be caused by the metering substance becoming clogged in part of the metering system after its pot life or the metering substance having to be removed from the metering system with great effort. Cleaning the metering system can mean an occasional shutdown of the metering system and unnecessarily increases operating costs.

In addition, however, in conventional metering systems the (environmental) conditions outside the metering system can also have an adverse effect on the pot life of the metered substances. In particular, the high ambient temperature of the metering system can lead to heating of the metering substance from outside the metering system in regions of the metering system which are not heated directly or indirectly by the metering system, which can shorten the pot life. This is especially critical in metering requirements that require very low metered material throughput. As mentioned, shortening the pot life inhibits efficient and as uninterrupted as possible operation of the metering system.

Disclosure of Invention

It is therefore an object of the present invention to provide a metering system for metering a substance and a method for operating such a metering system, by means of which the aforementioned disadvantages can be avoided and the efficiency of the metering system can be improved.

This object is achieved by a metering system according to claim 1 and a method for operating a metering system according to claim 11.

The metering system according to the invention for metering a substance comprises a metering device having a housing, which is optionally also multi-part, wherein the housing has at least one inlet channel for metering the substance, a nozzle, a spray element and an actuator unit coupled to the spray element and/or the nozzle. In the following, the ejector element is also used synonymously as tappet, without restricting the invention.

The metered substance is output from the metering system according to the invention in the manner described at the beginning, i.e. the metering system is not limited to a specific ejection principle. In this way, it is possible, as is the case in most cases, to arrange a spray element which can be moved at a relatively high speed in the nozzle of the metering system (in particular in the region of the nozzle, for example, immediately before the outlet) and which serves to eject the metered substance from the nozzle. Alternatively or additionally, the outlet opening of the metering system according to the invention may be configured to be movable as described. For the sake of clarity, it is therefore mentioned below that the metered substances are dispensed by means of a movable ejection element, for example a tappet. The invention should not be so limited.

The actuator unit of the metering device may comprise one or more actuators, wherein the respective actuator may be realized according to the actuator principle described at the outset. The present invention is described below in terms of a metrology system having a piezoelectric actuator, but is not limited thereto. Regardless of the specific design, the actuator unit is enclosed by the housing of the metering device, i.e. is isolated from the ambient atmosphere of the metering system.

The actuator unit is at least occasionally functionally coupled with the jet element or nozzle. The coupling is made by transmitting the force and movement exerted by the actuator to the spray element or nozzle so that a desired, preferably vertical, movement of the spray element and/or nozzle is thereby achieved for outputting the metered substance from the nozzle. Depending on the specific actuator principle, the actuator can act directly, i.e. without further motion-transmitting components, on the ejection element. The actuator unit of the metering system may also comprise a movement mechanism in order to transmit the movement or deflection of the (piezo) actuator to the jet element via a distance. Preferably, the coupling between the actuator and the ejector element or between the movement mechanism and the ejector element is not a fixed coupling. This means that the respective components are preferably not joined by screwing, welding, gluing, etc. to each other.

The components of the metering device which come into contact with the metered substance, i.e. for example the feed channel, the nozzle and the spray element, can preferably be combined in the fluid unit of the metering device, for example as a structural unit. The fluid unit and the actuator unit can be enclosed in separate partial housings, which can be interconnected with one another, preferably without tools, to form a metering device, i.e. the housing can be designed in multiple parts.

Furthermore, the at least one metered substance storage holder is directly coupled to the housing of the metering device. A metered-substance storage holder or metered-substance receptacle is understood to be the area of the metering system in which fresh metered substances are stored or held until processing. The metering substance storage holder can be mounted on the housing of the metering device itself at least at times, in particular during operation of the metering system, by means of a coupling point or port of the metering device. In the case of the two-part housing described above, there can be a coupling to the actuator unit and/or the fluid unit. The coupling points are particularly preferably arranged in the region of the fluid cells. This means that the metered substance storage holder and the metering device may be "kinematically connected" at least temporarily as a unit.

Alternatively, the metered substance storage holder may also be integrated, preferably fixedly, into the housing of the metering device. In this case, the housing can have, for example in the case of a multi-part housing, preferably in the region of the fluid unit, a cavity which is accessible from outside the metering system and is used for receiving or storing the metered substances. The metered substance reservoir holder may also be realized by means of an "metered substance tank" which is external or external to the housing and is fixedly connected thereto. Regardless of the specific design of the metered-substance storage holder, the metering system according to the invention comprises at least one metering device as described at the outset, which comprises a housing, and a metered-substance storage holder which can be coupled to it in situ as a structural unit or integrated into the housing.

According to the invention, the metering system also has a plurality of individually controllable temperature control devices, which are each associated with a different defined temperature zone of the metering system in order to control the respective temperature zone differently. The metering system comprises at least two, preferably at least three, separate temperature zones.

A temperature zone is understood to be a limited, defined (sub-) region or section of the metering system, preferably a cavity of the metering system filled with the metering substance. The cavity may comprise a dosing substance having a specific (nominal) temperature and/or a specific (nominal) viscosity. That is, the temperature zone comprises at least one temperature-adjustable metered substance volume in a defined area of the housing and/or the metered substance storage holder. Preferably, the temperature zone may also comprise a section of the metering system which encloses the metered substance volume or defines an area of the metering system which is external to the temperature zone, such as a plurality of wall or housing sections.

The respective temperature control device is designed to control the temperature of the metering substance contained in the respectively assigned partial region of the metering system, i.e. in the temperature region or interacting therewith, to different (nominal) temperatures, for example in order to achieve different (nominal) viscosities of the metering substance. However, the (fixed) components of the metering system can also be (simultaneously) tempered by means of the tempering device. The aim of temperature control is, however, to set the metered substances simultaneously to different temperatures or viscosities in two or more defined regions of the metering system, i.e. in a plurality of temperature zones, by means of corresponding temperature control devices.

The temperature control is carried out during operation of the metering system, i.e. during the flow of the metering substance through the respective temperature zone or in the arrangement thereof. In this case, the temperature control devices are designed and arranged in the metering system in such a way that in each case one temperature control device can control the temperature of a particular (corresponding) temperature zone, in particular of the metered substances therein.

In the context of the present invention, tempering is understood to mean the transfer of thermal energy into the metering substance or the removal of thermal energy from the metering substance. If necessary, both processes can also be performed simultaneously. In this case, the individual temperature control devices can each comprise at least one heating device and one cooling device, wherein temperature control can take place by means of conduction and/or convection, as will be described below. The heating device and the cooling device of the respective temperature control device can preferably be operated separately by means of separate control and/or regulating circuits of the control and/or regulating unit of the metering system. This will be described in detail later.

According to the invention, at least one first temperature zone is assigned to the metered-substance storage holder, wherein a second temperature zone is assigned to the nozzle. The nozzle can preferably have a (hollow) interior space filled with the dosing substance, which interior space is referred to as the nozzle chamber. Preferably, the second temperature zone is provided to the nozzle chamber. This means that the temperature control device is designed to control the temperature of the metered substance in at least one region of the metered substance storage holder differently than in the region of the nozzle, preferably lower, in particular differently than in the nozzle chamber of the nozzle. The two temperature zones are preferably separated from one another by an inlet region or inlet channel for the metered substances, i.e. they are preferably not directly adjacent to one another.

According to the invention, at least one of the temperature control devices, preferably at least the temperature control device provided for the metered-substance storage holder, comprises a cooling device having at least one cooling source. The refrigeration source is preferably designed to actively remove thermal energy from the substance, thereby generating a specific refrigeration capacity. The refrigeration source may perform a refrigeration process, i.e. the refrigeration source may actively "generate" cold. A cooling source can also be understood physically as a heat sink.

The source of refrigeration is configured and cooperates with the cooling device such that the cooling device can use the cold "generated" by the source of refrigeration to cool the metered substance. According to an embodiment, the refrigeration source itself may form substantially the entire cooling device. Alternatively or additionally, however, the refrigeration source can also be coupled to a cooling device, as will also be described later.

The cooling device is designed to cool the corresponding temperature zone, in particular the dosing substance in the temperature zone, to a specific (nominal) temperature. For cooling, heat or thermal energy can be removed from the metered substance in a targeted manner by means of a cooling device, for example by means of convection and/or conduction. In particular, the dosing substance can be cooled by means of a cooling device to a temperature which is significantly below the ambient temperature of the dosing system. Preferably, the metering substance can be tempered by means of a corresponding tempering device, in particular a cooling device, to a (nominal) temperature of at most 18 ℃, preferably at most 3 ℃, particularly preferably at most-30 ℃.

The embodiment according to the invention with a plurality of temperature control devices for different temperature zones has various advantages:

on the one hand, a high degree of accuracy in the discharge of the metered substances can be achieved by means of the metering system according to the invention, which can be achieved by controlling the temperature of the metered substances to an optimum process temperature in the region of the nozzles by means of a corresponding temperature control device.

On the other hand, the metered substance can be cooled in the region of the metered substance storage holder by means of a corresponding temperature control device to a temperature significantly below the processing temperature, for example the storage temperature, in order to keep the metered substance in the metering system stable over a longer period of time. Advantageously, the metering substance in the metering substance reservoir holder can be cooled such that it reaches the nozzle at a non-critical (nominal) temperature and is brought to the processing temperature shortly before being ejected from the nozzle, i.e. in the nozzle itself, for example to reach a suitable viscosity for ejecting the metering substance. The disadvantageous effect of the (high) processing temperature on the processability of the metering substance can thus be reduced as much as possible, which improves the effectiveness of the metering system. Particularly at high ambient temperatures and/or with low throughput of metered substances, an undesirable shortening of the pot life can be effectively suppressed.

The method according to the invention for operating a metering system for metering a metered substance relates to a metering system having a metering device with a housing, which may also be multi-part, wherein the housing comprises at least one inlet channel for the metered substance, a nozzle, a spray element and an actuator unit coupled to the spray element and/or the nozzle. The metering system also has a metered substance storage holder coupled directly to or integrated into the housing.

According to the invention, a plurality of defined temperature zones of the metering system are differently tempered by means of a plurality of individually controllable tempering devices of the metering system, wherein the tempering devices are each associated with a temperature zone. In order to correspondingly regulate the temperature of the temperature zones, in particular of the metered substances in the respective temperature zones, the temperature regulation devices can be individually controlled and/or regulated by means of a control and/or regulating unit of the metering system.

According to the invention, at least two, preferably at least three, temperature zones of the metering system are each tempered differently by means of a corresponding tempering device. In the method according to the invention, at least one first temperature zone associated with the metering substance storage holder is tempered differently from a second temperature zone associated with the nozzle.

Preferably, at least one of the temperature zones, preferably at least the temperature zone provided for the metered-substance storage holder, is tempered by means of a cooling device (having a refrigeration source) of the corresponding tempering device.

Further particularly advantageous embodiments and refinements of the invention emerge from the dependent claims and the following description, wherein the independent claims in one claim category can be modified analogously to the dependent claims in another claim category and as an embodiment, and in particular individual features of different embodiments or variants can also be combined to form a new embodiment or variant.

Preferably, the metering system comprises at least one further individually controllable tempering device, which is assigned to the third temperature zone of the metering system. Preferably, the third temperature zone is assigned to the feed channel of the metering system in order to bring the metering substance in the feed channel to a (nominal) temperature, wherein the (nominal) temperature can be different from the corresponding (nominal) temperature of the metering substance in the metering substance reservoir holder and/or the nozzle. The temperature control device of the metering system is preferably designed to set a "temperature gradient" of the metered substance in different regions of the metering system in a targeted manner, as will be described later.

The temperature control device associated with the supply duct preferably also comprises a cooling device as described above, which has a cooling source. The temperature control device associated with the nozzle can also comprise such a cooling device with a cooling source. Preferably, the individual cooling devices can be individually actuated.

An inlet channel or inlet region is understood to be a (sub-) region of the metering system which extends from the metered-substance storage holder up to the nozzle. In contrast to the metered-substance storage holder (except when the metering system is shut down), the feed channel is not the main (long-term) reservoir for the metered substance, but is flowed through by new metered substance more or less continuously during operation. Preferably, the inlet channel extends between a coupling point for the couplable metered-substance storage holder and the interior of the nozzle or the beginning of the nozzle chamber of the nozzle.

In a particularly preferred embodiment of the metering system, the metering system comprises three different temperature zones to be tempered. Preferably, the respective temperature zone can completely enclose the closed functional unit or functional part of the metering system, i.e. for example the entire metered-substance storage holder. It is therefore particularly preferred that the respective temperature control device can be designed or assigned to the respective temperature zone in order to control the temperature of substantially all the metered substances in the feed channel or substantially all the metered substances in the nozzle "mostly" uniformly.

Preferably, the respective temperature zones may directly adjoin each other or be connected to each other without interruption. The boundary between the two temperature zones is a temperature transition zone. This means that the metering substance is not suddenly tempered to a new (nominal) temperature after passing through the temperature zone boundary, but rather has this temperature continuously due to the flow. By "largely" uniformly temperature-controlled, it is meant that there can be regions of the temperature range, for example regions in the region of the temperature range boundary, in which the metered substance (still) does not have a corresponding (nominal) temperature.

Advantageously, the third temperature control device of the metering system can be used to reliably maintain the metered material in the respectively desired or advantageous (target) temperature range from the point in time at which it is supplied (in the metered material storage holder) until the actual processing thereof (in the nozzle). Advantageously, it is achieved thereby on the one hand that the metering substance is continuously kept below the processing temperature of the metering substance even when the throughput of the metering substance is very low until the nozzle is reached, wherein a shortening of the pot life can be effectively suppressed. This is advantageous in particular when working thermally hardening metering substances, such as adhesives.

On the other hand, however, a third temperature control device which can be controlled separately can also be used to bring the metered substances stepwise to the process temperature. In the case of very high throughputs of the metered substances, it can be advantageous to bring the metered substances, which are ejected from the metered substance storage holder and which may be very cold in the feed channel, to a new, higher (nominal) temperature (but below the process temperature) by means of a corresponding temperature control device. The input channel may be used to "pre-temper" the metered substance in order to reduce the temperature difference between the metered substance discharged from the metered substance reservoir holder and the process temperature. In this way, the metering substance can be brought to the processing temperature in the nozzle itself despite the very high throughput of metering substance, so that the action time of the (high) processing temperature on the metering substance or the undesired effects obtained thereby can be kept as low as possible.

In the present invention, it is also possible for the respective temperature zones not to be directly adjacent to one another, i.e. there may be "gaps" between the temperature-adjustable temperature zones. The metering system may comprise (sub-) areas which are not equipped with a tempering device. The temperature control device can therefore be designed to control the temperature only in at least one partial sub-area of the metered-substance storage holder or of the feed channel or of the nozzle, wherein no other areas of the aforementioned components are (directly) involved in the temperature control. For example, the metered material in the silo can be actively cooled to maximize the pot life, before the temperature is actively adjusted again in the nozzle in order to achieve processing of the metered material.

For cooling the metered substances, each tempering device of the metering system can comprise an individually controllable cooling device. The respective cooling device uses the cold provided by means of a refrigeration source as described.

The first embodiment of the cooling device according to the present invention may be such that the refrigeration source is configured as a main component of the cooling device. This means that the cooling device and the refrigeration source can form a preferably fixedly connected unit. The cooling device can be designed to cool the metered substances of the respective temperature zones in contact, i.e. without the use of a flowing cooling fluid, to a (nominal) temperature, for example by means of conduction cooling. Preferably, the refrigeration source may utilize the principles of thermoelectric cooling. Preferably, each cooling device according to this embodiment may comprise at least one (own) cooling source.

For example, the cooling device can comprise at least one peltier element (as a cooling source) which is arranged on the housing or on the metered substance storage holder by means of a holding device (as a component of the cooling device) in order to convey the cold to the metered substance in the respective temperature range as far as possible without losses.

According to a second embodiment of the cooling device, a single refrigeration source can be made to function in common with a plurality of, preferably all, cooling devices of the metering system.

Preferably, the refrigeration source can then be (releasably) coupled to a plurality of individually actuatable partial cooling circuits. Preferably, the refrigeration source can be in operative contact with at least two, preferably at least three, separately operable partial cooling circuits.

Preferably, each such individually actuatable partial cooling circuit is configured to temper the metered substance in a respective specific temperature zone. This means that the respective cooling circuit is assigned to a specific temperature range. Each partial cooling circuit may thus form a cooling device for a corresponding temperature zone.

Preferably, the respective partial cooling circuit comprises a plurality of cooling components or "cooling bodies", which are preferably arranged in the region of the housing or the metered-substance storage holder. Preferably, part of the cooling circuit is configured to supply the "cooling body" with a flowing gaseous and/or liquid pre-cooled coolant at a specific (nominal) temperature. The respective "cooling body" can preferably be designed according to the type of heat exchanger in order to transfer the cold from the pre-cooled coolant to the metering substance as efficiently as possible or to remove the heat therefrom, respectively.

Preferably, the respective "heat sink" comprises at least one inlet for pre-cooled coolant, for example a connection point for an external coolant supply line. In order to form part of the cooling circuit, the "cooling body" of the respective cooling device can be coupled to the refrigerant source by means of a separate refrigerant supply line, for example a temperature-isolated flexible line. In addition, the "heat sink" can comprise an outlet opening for the coolant, for example a connection point for a separate coolant outlet line, in order to feed the possibly heated coolant to the cooling source again.

The plurality of partial cooling circuits are preferably designed to utilize the cold of the common cooling source. The cooling source is preferably designed and can be actuated to selectively supply the cooled coolant of different temperatures to the individual partial cooling circuits.

In order to control the cooling capacity of the respective cooling device, the (nominal) temperature of the coolant flowing into the cooling device is controlled by means of a control unit of the metering system. Alternatively or additionally, the volume flow of the coolant in the respective partial cooling circuit can be controlled, for example, by means of a separately actuatable proportional valve and/or pump.

In the following description, the cooling device according to the second embodiment describes a metering system in which a common cooling source provides cold for a plurality of partial cooling circuits. The invention should not be so limited.

The refrigeration source is preferably designed to cool the gaseous and/or liquid coolant to a specific (nominal) temperature, i.e. to specifically remove heat or thermal energy from the coolant. Preferably, due to the active cooling, the (nominal) temperature of the coolant may be lower than the ambient temperature of the metering system. The cooling agent can be cooled by means of a cooling source such that the cooling agent has a (nominal) temperature of at most 18 ℃, preferably at most 3 ℃, particularly preferably at most-30 ℃ in the region of the respective temperature control device.

The cooling source, which may also be referred to as a "cold producing device", may be constructed separately, i.e. not as a fixed component of the metering system. For example, the cooling source can be arranged "remote" from the metering system, wherein the cooling device is supplied with coolant by means of a separate cold transfer device, for example a separate coolant supply line.

Preferably, the refrigeration source according to the first embodiment can be operated irrespective of the temperature and/or humidity of the ambient air of the metering system or of the cold generating device. This means that the temperature of the coolant can be lowered with respect to the ambient temperature by means of the refrigeration source and can be set to "arbitrary", i.e. to a value required for the operation of the metering system. Preferably, the refrigeration source may use the principles of a refrigeration machine. For example, the refrigeration source may comprise a compression refrigeration device. Preferably, such a refrigerator is designed to supply a plurality of tempering devices, if appropriate also tempering devices of different metering systems, with pre-cooled coolant. Suitable coolants are liquid and/or gaseous media, coolants having a high heat capacity being preferred.

Preferably, compressed and (actively) cooled air can be used as coolant, since the air can be provided at relatively low cost and can be coordinated with the hygroscopic properties of the piezoelectric actuator under stress. In a second embodiment of the invention, the cooling source can therefore be realized by means of at least one vortex tube. The vortex tube is configured to cool the coolant to a particular (nominal) temperature.

Preferably, the cooling device may also comprise more than one, i.e. at least two, refrigerant sources. In particular, a plurality of cooling sources can be configured to be individually controllable. If the cold used by the cooling device is generated by two or more separate "cold generating" components (cold sources), reference will be made below to a "multi-part" cold source.

For example, a multi-part cooling source can be realized by means of a plurality of vortex tubes. Preferably, each vortex tube can supply a single partial cooling circuit with pre-cooled coolant.

The temperature of the cooled air discharged from the respective vortex tube can preferably be regulated in the region of the hot air outlet of the vortex tube by means of an adjustable regulating valve. Alternatively or additionally, the volume flow of air flowing into the swirl chamber of the swirl tube can also be regulated, for example by means of a proportional valve connected upstream of the swirl tube.

Particularly preferably, the refrigeration source according to the third embodiment can comprise a refrigerator, for example a compression refrigeration device, and at least one downstream vortex tube (multi-part refrigeration source) interacting therewith. The coolant which has been pre-conditioned or cooled can preferably be finally cooled to the (nominal) temperature by means of a vortex tube. Due to this correlation, the coolant can also be cooled to a temperature below the "as low as possible" cooling temperature of the refrigerator. In this embodiment, it is also possible to have a (downstream) vortex tube in each case interact with a part of the cooling circuit.

Advantageously, this can be achieved by means of a refrigeration source, which always provides a sufficiently large amount of sufficiently cooled coolant in order to cool the metered substances in one or more temperature zones to a specific (nominal) value, respectively. In this way, the metered substance can also be held in the metering system for a relatively long period of time in adverse environmental conditions, for example at particularly high air temperatures. In particular, a very wide and very low cooling control range of the metered substances can be achieved with the aid of a refrigerant compressor device in conjunction with a (downstream) vortex tube.

It is also advantageous to provide a multi-part refrigeration source with a plurality of, i.e. two or more (downstream) vortex tubes, in order to be able to supply differently conditioned coolants to the individual cooling devices, in particular to parts of the cooling circuit. This also enables the temperature control of the respective temperature control zone to be optimally adapted to the dynamic metering requirements, which will be described later.

In the present invention, the refrigeration source can also be fixedly coupled to the cooling device, as described above, for example by means of a peltier element arranged on or in the housing. Such a design of the cooling source is advantageous, for example, when a punctiform or locally defined cooling effect is required. For example, the region of the nozzle pointing in the direction of the actuator unit and/or the outer region of the nozzle or of the housing can be cooled in a targeted manner.

In order to match the temperature of the metered substances in the metering system as dynamically as possible to the current metering requirements, the temperature control devices can each comprise a heating device. Preferably, the temperature control device associated with the metered-substance storage holder and/or the temperature control device associated with the supply channel and/or the temperature control device associated with the nozzle can each have at least one heating device in order to heat the metered substance in the respectively corresponding temperature zone to a specific (nominal) temperature.

Preferably, the cooling device and the heating device of the respective temperature control device are designed to be individually controllable. Preferably, the two components are each designed to be spatially separated from one another, in particular each by means of a separate element. Particularly preferably, different (temperature control) media for temperature control of the metered substances can be used for the heating device and the cooling device.

Preferably, the respective cooling and heating devices are arranged in the metering system such that the metered substances in the corresponding temperature zones can be brought as efficiently as possible to the (nominal) temperature. Preferably, the cooling device and the heating device of the respective tempering device are in effective contact with the metered substance of the respectively corresponding temperature zone.

The corresponding heating device can be realized by means of at least one electrically heatable element, for example a heating wire and/or a heating core in the region of the housing or the nozzle. The temperature of the metered substance is regulated by means of conduction, i.e. without direct contact between the heating device and the metered substance.

In connection with the metering substance it may be advantageous to heat the metering substance in the region of the metering substance storage holder as well. The metered-substance storage holder may, on the one hand, be arranged fixedly in the region of the housing as described. The metered substance storage holder may alternatively comprise a metered substance storage container coupled to the housing.

Preferably, the metered substance storage holder is realized by means of at least one metered substance storage container. The metered-substance storage container, also referred to as a metered-substance silo, can preferably be mounted directly on the housing, at least from time to time. Particularly preferably, the metered material silo may comprise a silo coupling point, so that the entire silo is reversibly fixed on the coupling point of the housing.

In order to effectively cool the metered substances in the silo or in the coupled metered substance storage holders, a coolant can be flowed or blown from the outside to the silo by means of a corresponding cooling device. Preferably, however, the metering system may comprise a "silo-accommodating unit" into which the silo is accommodated completely in the state of being installed as intended, i.e. when the silo is coupled to the housing in operation. Preferably, the silo containment unit is configured such that the installed silo is substantially hermetically isolated from the ambient atmosphere of the metering system.

Preferably, the silo receiving unit may comprise a closable opening for accessing the silo and an inlet opening for pre-cooled coolant or a coupling point for external coolant supply. Preferably, the flow channel for the coolant (as "cooling body") may be configured in the region between the silo and the wall of the silo accommodating unit which surrounds the silo from the outside. The silo receiving unit may further comprise a heating device, for example in an area of a wall of the silo receiving unit facing the silo.

In order to bring the metered substance to a specific (nominal) temperature in the metered-substance storage holder, the corresponding temperature control device can be actuated by means of the control unit and/or the control unit. The remaining temperature control devices can preferably also be equipped with corresponding control and/or regulating units, which are designed to individually control and/or regulate the cooling and/or heating devices of the respective temperature control device. Preferably, the metering system can comprise only one (common) control unit and/or regulating unit in order to actuate the respective temperature control device by means of a separate control and/or regulating circuit, respectively.

The term control is used below as a synonym for control and/or regulation. This means that, when referring to control, the control may comprise at least one regulating process. During the regulation, the regulating variable (as actual value) is usually continuously detected and compared with a reference variable (as setpoint value). The adjustment is usually performed in such a way that the adjustment variable is calibrated to the reference variable. This means that the control variable (actual value) influences itself continuously in the operating path of the control loop.

The control unit is preferably designed to control and/or regulate the respective temperature control device in such a way that the metered substances are controlled to a respectively predetermined, preferably different (nominal) temperature in the respectively corresponding temperature range.

Preferably, the tempering device can be controlled such that the metered substances are cooled purely, i.e. only the cooling means are operated.

Alternatively, only the heating device of the temperature control device can also be controlled by means of the control unit. Preferably, the heating power of the heating device is controlled for tempering the metered substance, i.e. for setting and maintaining the (nominal) temperature of the metered substance, for example by controlling the intensity of the current supplied to the heating device.

However, the cooling device and the heating device can also be operated at least temporarily in parallel, i.e. the metered substances in the same temperature range can be cooled and heated simultaneously ("principle of superimposed" regulation). Preferably, the cooling device and the heating device are operated or operated as independently of one another as possible. However, it is preferred to take into account the current state of the respective other "opposite" component (for example, that component is currently "active" or "inactive") when controlling the respective component (cooling device or heating device). The "superimposed regulation" is preferably controlled such that the consumption of thermal energy or cooling medium is as low as possible, i.e. the heating device and the cooling device are not continuously operated at full load relative to each other.

Advantageously, by means of the principle of "superimposed regulation", it is possible to avoid as far as possible an "overflow" of the metering substance temperature beyond a predetermined (nominal) temperature. Additionally, a small controlled "relative operation" of the heating means and the cooling means helps to increase the "intensity" or stability of the temperature of the metered substance with respect to the effects of external disturbances.

It is also advantageous if the metering system is based on separately controllable heating and cooling devices, in particular also in the region of the metered-substance storage holder, for processing hot-viscous metered substances. Advantageously, only the hot viscous substance in the region of the metering substance storage holder is liquefied first, so that the metering substance in the metering system can flow. The viscosity of the hot-tack material can then be reduced (by heating to the processing temperature) in the nozzle so that the metered material can be ejected from the nozzle. The energy requirement for heating the metering substance can thereby be reduced compared to the permanent holding of the metering substance in the metering system at the processing temperature.

The (nominal) temperature of the metering substance in the respective temperature range can preferably be determined in the temperature management of the metering substance. Preferably, the control unit is designed to calculate and/or carry out a particularly economical temperature management of the metered substances, i.e. to operate the respective temperature device accordingly. The temperature management can preferably be such that, on the one hand, an optimum processing of the metered substance (on ejection) and, on the other hand, as long a pot life as possible of the metered substance in the metering system is achieved.

In the case of temperature management, the control unit can be designed to control and/or regulate a corresponding temperature control device for controlling the temperature of the metered substances as a function of at least one input parameter. The individual temperature devices can be controlled individually, i.e. in accordance with the same or respectively different input parameters.

Preferably, the control unit can be configured to control or determine the (nominal) temperature of the at least one temperature zone as a function of the input parameters.

The input parameters may be stored in the control unit and/or derived by means of sensors of the metering system, as will be described below. Preferably, the respective temperature control device can be controlled, in particular regulated, as a function of one or more input parameters (as actual values) such that the metered substances in the respectively associated temperature range, preferably in substantially all temperature ranges, reach a specific (respective) setpoint value as quickly as possible and/or such that the setpoint value is kept as constant as possible during operation. Preferably, the setpoint value of the metering substance in the respective temperature range is kept constant by the regulation even at high metering substance throughputs and/or dynamic metering requirements. The target value can be, for example, the (target) temperature and/or the (target) viscosity of the metering substance.

The first input parameter may be the volumetric flow rate of the metered substance or the metered substance throughput per unit time in a temperature zone. Preferably, the (nominal) temperature of a temperature zone can be dynamically controlled (determined) as a function of the current and/or expected volume flow of the dosing substance in at least one, preferably in the same, temperature zone.

Alternatively or additionally, the temperature of the dosing substance in the at least one temperature zone may also be an input parameter for the control unit. In a further embodiment, the metering system can be provided with a temperature sensor for generating input parameters for controlling the temperature control devices.

Preferably, the metering system comprises a plurality of temperature sensors in order to individually determine the temperature of the metered substance in the region of the metered substance storage holder, the input channel and the nozzle. The respective sensor may be arranged in direct measuring contact with the dosing substance. Alternatively, the sensor is configured to derive or extrapolate the temperature of the metered substance over a time interval.

The third input parameter may be the viscosity of the metered substance in at least one temperature zone. Preferably, the (nominal) temperature of the at least one temperature zone can be dynamically controlled (determined) as a function of the viscosity of the dosing substance.

In order to adjust the temperature control, for example, in order to achieve a specific (nominal) viscosity of the metered substances, the input parameters can be determined individually in the temperature range by means of suitable sensors, for example, a viscometer. Alternatively, the (actual) viscosity of the dosing substance can also be calculated, for example, by means of the viscosity of the dosing substance (under standard conditions) stored in the control unit and the conditions prevailing at the moment in the dosing substance.

Advantageously, the individual temperature control devices can be controlled by means of a metering system, in particular by means of a control unit, in order to achieve the (target) temperature of the metered substance in the respective temperature zone as efficiently as possible.

On the other hand, the control device can also be used to continuously re-determine the respective temperature zone or the (target) temperature to be achieved in the metering material during operation and thus to adapt the current situation of the metering process. External "disturbing factors" (e.g. fluctuating ambient temperatures) and/or internal fluctuations (e.g. significantly varying metering material throughputs) can thus be compensated as far as possible during operation, wherein adverse effects on the properties of the metering material are avoided. This makes it possible to achieve particularly high metering accuracy and at the same time suppress a reduction in pot life.

The aforementioned temperature management of the dosing substance can preferably also be taken into account in the method for operating the dosing system, which will be described below.

In a preferred method, the temperature zones associated with the nozzles are conditioned by means of corresponding conditioning devices in such a way that the temperature of the metered substance in preferably substantially the entire temperature zone corresponds to at least one specific processing temperature of the metered substance. The temperature can preferably be adjusted such that the temperature of the dosing substance is higher than the ambient temperature of the dosing system.

The temperature zone associated with the metered-substance storage holder can preferably be tempered such that the temperature of the metered substance in the temperature zone, preferably substantially the entire temperature zone, is lower than the temperature of the metered substance in the temperature zone associated with the nozzle or in the nozzle. Alternatively or additionally, the temperature can also be adjusted such that the temperature of the metered substance in the metered-substance storage holder is below the ambient temperature of the metering system.

The temperature of the temperature region of the supply channel associated with the metering system is preferably adjusted such that the temperature of the metered substance in this temperature region, preferably substantially in the entire supply channel, is higher than the temperature of the metered substance in the temperature region associated with the metered substance storage holder or in the metered substance storage holder. Alternatively or additionally, the temperature can also be adjusted such that the temperature of the metering substance in the supply channel is lower than the temperature of the metering substance in the temperature zone associated with the nozzle. In order to bring the metered substances to the respectively determined (target) temperature in the respective temperature range, the cooling device and the heating device of the respectively associated temperature control device can be controlled individually by means of the respectively individually designed control circuit of the control unit.

In particular, it is preferred, as described above, to control the respective temperature control device, i.e. the temperature control devices associated with the metered-substance storage holder, which may be associated with the feed channel, and with the nozzle, individually by means of the control unit, such that a defined temperature gradient of the metered substance is formed in the metering system. Preferably, the control of the temperature gradient may be configured such that the temperature of the metered substance in the metered substance reservoir holder is lower than the temperature of the metered substance in the inlet channel, wherein the temperature in the inlet channel is lower than the temperature of the metered substance in the nozzle.

In the method, the respective temperature control device is preferably controlled in such a way that the metered substances are gradually heated in the process, preferably from a stable storage temperature to the processing temperature. Preferably, the temperature of the metering substance is controlled such that it corresponds to the processing temperature only as briefly as possible, i.e. the metering substance reaches the final processing temperature as late as possible in the process, preferably only immediately before the injection process.

In the temperature management, the (setpoint) temperature of the respective temperature zone of the metering system, i.e. of the metering substance in the temperature zone associated with the metering substance storage holder and/or in the temperature zone associated with the supply channel and/or in the temperature zone associated with the nozzle, is determined by the control unit as a function of the actual and/or expected throughput of the metering substance in the respective temperature zone. In particular, the (nominal) temperature can also be dynamically adapted to fluctuations in the throughput of the metered substance.

Finally, for the sake of completeness only, the corresponding temperature control device can also be designed to control the temperature of the temperature zones in substantially the same way. The control unit can thus individually control the temperature control devices in such a way that the metered substances are controlled to substantially the same temperature in the respective temperature zones.

Drawings

The invention is explained in detail again below on the basis of embodiments with reference to the drawings. The same reference numerals are used here for the same components in different figures. The drawings are not generally shown to scale. The figures show that:

figure 1 shows a cross-sectional view of a metering system according to an embodiment of the present invention,

figure 2 shows part of a metering system according to another embodiment of the present invention,

figure 3 shows part of a metering system according to another embodiment of the present invention,

figure 4 shows part of a metering system according to another embodiment of the present invention,

figure 5 shows part of a metering system according to another embodiment of the present invention,

fig. 6 shows a schematic view of a tempering system of a metering system according to an embodiment of the present invention.

Detailed Description

A specific embodiment of a metering system 1 according to the invention will now be described with reference to fig. 1. The metering system 1 is shown here in a generally intended position or location, for example when the metering system 1 is in operation. Here, the nozzle 40 is located in a lower region of the metering system 1, so that a drop of the medium can be ejected downwards through the nozzle 40 in an ejection direction R. The terms lower and upper will be used below for this, so that the description always refers to this more or less common orientation of the gauging system 1. However, this does not exclude that the metering system 1 can also be used in special applications in different orientations and that the droplets are ejected, for example, laterally. This is also possible in principle, depending on the medium, the pressure and the specific construction and the manipulation of the entire injection system.

The metering system 1 comprises as main components an actuator unit 10 as well as a fluid unit 30 and a metering substance storage holder 70 coupled to the fluid unit 30, the actuator unit 10 and the fluid unit 30 together forming a metering device 5.

In the exemplary embodiment of the metering system 1 shown here, the actuator unit 10 and the fluid unit 30 are fixedly connected to one another, for example by means of fastening screws 23, and thus form a housing 11 having two housing parts 11a, 11 b. It should be noted, however, that the individual components 10, 30 can also be realized as quick couplings (schnellkupsplung) depending on the type of plug-in coupling parts that are to be coupled to one another. The actuator unit 10 and the fluid unit 30 may then be coupled to each other without tools to thereby form the metering system 1. The actuator unit 10 and the fluid unit 30 together form the metering device 5 of the metering system 1.

The actuator unit 10 basically includes: all the components for driving the ejection element 31, here the tappet 31, or moving the ejection element 31, here the tappet 31, in the nozzle 40, i.e. the piezoelectric actuator 60 and the movement mechanism 14, for example, in order to be able to operate the ejection element 31 of the fluid unit 30; the control unit 50 is such as to be able to operate the piezoelectric actuator 60 and similar components as will be explained below.

The fluid unit 30 comprises, in addition to the nozzle 40 and the feed line 80 for feeding the medium into the nozzle 40, all other components which are in direct contact with the medium and also elements which are required for mounting the relevant components in contact with the medium together or for holding them in their position on the fluid unit 30.

In the exemplary embodiment of the metering system 1 shown here, the actuator unit 10 comprises an actuator unit housing block 11a as a first housing part 11a, which has two chambers disposed inside, namely an actuator chamber 12 and a piezo actuator 60 located therein, and a motion chamber 13 into which a movable ejection element 31 of the fluid unit 30, in this case a tappet 31, projects. The tappet 31 is actuated by the movement mechanism 14, which projects from the actuator chamber 12 into the movement chamber 13, by means of the piezo actuator 60, so that the medium to be metered is discharged by the fluid unit 30 in a desired amount at a desired point in time. The tappet 31 closes the nozzle opening 41 and therefore also serves as a closure element 31. However, the tappet 31 is also referred to as the injection element 31 here, since the majority of the medium is ejected from the nozzle opening 41 only when the tappet 31 is moved in the closing direction.

In order to actuate the piezo actuator 60, the piezo actuator 60 is electrically connected or connected by signal technology to the control unit 50 of the metering system 1. The connection to the control unit 50 is effected via a control cable 51, the control cable 51 being connected to a suitable piezo actuator control connection 62, for example a suitable plug. The two control connections 62 are each coupled to a contact pin 61 of the piezo actuator 60 or to a corresponding connecting pole in order to actuate the piezo actuator 60 by means of the control unit 50. In contrast to the illustration in fig. 1, the control connections 62 pass through the housing 11 in a sealed manner, so that substantially no air can enter the actuator chamber 12 from the outside in the region of the respectively passing control connection 62, for example in order to cool the actuator 60 effectively. For this purpose, the actuator chamber 12 comprises an inlet opening 21 for a coolant in the upper region in order to charge the piezo actuator 60 with coolant. The piezo actuator 60, in particular the piezo actuator control connection 62, can be provided, for example, with a suitable memory unit (for example EEPROM or the like), in which information such as the name of the article or the setting parameters of the piezo actuator 60 are stored, which can then be read by the control unit 50 in order to identify the piezo actuator 60 and be manipulated in a suitable manner. The control cable 51 may include a plurality of control lines and data lines. However, since the basic operation of piezo actuators is known, this is not described in detail.

The piezoelectric actuator 60 can be expanded (expanded) in the longitudinal direction of the actuator chamber 12 and contracted again by means of the control device 50 according to the wiring. The piezoelectric actuator 60 may be placed into the actuator chamber 12 from above. The height-adjustable spherical cap can then be used as an upper support (not shown here) by means of a screw movement, wherein the piezo actuator 60 can be precisely adjusted relative to the movement mechanism 14, here the lever 16. The piezo actuator 60 is thus supported on the lever 16 via the lower, acutely angled pressure piece 20, while the lever 16 rests on the lever bearing 18 at the lower end of the actuator chamber 12. The lever 16 is tiltable about a tilting axis K via a lever bearing 18, so that the lever arm of the lever 16 projects through the cutout 15 into the actuating chamber 13. The recess 15 connects the movement chamber 13 to the actuator chamber 12, so that coolant can flow from the actuator chamber 12 into the movement chamber 13 and can leave the housing 11 in the region of the outlet opening 22. In the actuating chamber 13, the lever arm has a contact surface 17 which is directed in the direction of a tappet 31 of a fluid unit 30 which is coupled to the actuator unit 10, the contact surface 17 pressing against a contact surface 34 of a tappet head 33.

It should be noted here that in the exemplary embodiment shown, the contact surface of the lever 16 is permanently in contact with the contact surface of the tappet head 33 by pressing the tappet spring 35 of the tappet head 33 against the lever 16 from below. Although the lever 16 is located on the tappet 31. But there is no fixed connection between the two parts 16, 31. In principle, however, there can also be a spacing between the tappet 31 and the lever 16 in the initial or rest position of the tappet spring 35, so that the lever 16, when pivoted downward, first runs freely over a specific displacement section and at the same time records the speed, and then strikes the tappet 31 or its contact surface 34 with a high pulse in order to increase the ejection pulse, which the tappet 31 applies to the medium. In order to achieve a constant pretension of the drive system (lever/piezo actuator/movement system) as possible, the lever 16 is pressed upward by the actuator spring 10 at its end which is in contact with the tappet 31.

The fluid unit 30 comprises a second housing part 11b and is connected here to the actuator unit 10 or its housing part 11a by means of the fastening screws 23 as described for forming the housing 11. The tappet 31 is supported by a tappet spring 35 on a tappet bearing 37, to which a tappet seal 36 is connected in a downward direction. The tappet spring 35 presses the tappet head 31 upward in the axial direction away from the tappet bearing 37. Thereby also pressing the tappet tip 32 away from the sealing seat 43 of the nozzle 40. In other words, in the rest position of the tappet spring 35, the tappet tip 32 is spaced apart from the sealing seat 43 of the nozzle 40, when no external pressure is exerted on the contact surface 34 of the tappet head 33 from above. Therefore, the nozzle opening 41 is also opened or not closed in the rest state (unexpanded state) of the piezoelectric actuator 60.

The nozzle chamber 42, to which the input channel 80 leads, delivers the metered substance to the nozzle 40. The other end of the feed channel 80 is connected to a metered material storage holder 70, the metered material storage holder 70 being realized here by means of a metered material silo 70. Together with the metering device 5, the metering material silo 70 forms the metering system 1.

The dosing silo 70 is fastened directly to the housing 11, in this case to the second housing part 11b, by means of a coupling point 77 at the coupling point 44 of the housing 11 interacting therewith. The ports 44, 47 enable the metered substance reservoir holder 70 to be reversibly secured to the housing 11 in a time-saving, preferably tool-free manner. Since the basic construction of the metering system is known, the components which are at least indirectly relevant to the invention are shown here primarily for the sake of clarity.

The metering system also comprises three temperature control devices 2, 2', 2 ″ which are each assigned to a different temperature zone of the metered substance. The first tempering device 2 is assigned to a dosing material silo 70. The tempering device 2 comprises cooling means 3 and heating means (not shown) which will be described below.

The metered-material silo 70 (only schematically illustrated here) is arranged in the specified state, i.e. coupled to the fluid unit 30, over the entire circumference within the silo receiving unit 72 of the cooling device 3. The silo receiving unit 72 is substantially hermetically closed by means of a cover and encloses an inlet 75 for pre-cooled coolant, for example a connection point for an external coolant supply line. The cooling channel 73 can be supplied with pre-cooled coolant by means of an inlet 75. The cooling channel 73 is arranged here in a wall 74 of the silo receiving unit 72 and is configured such that the cooling channel substantially helically surrounds the silo 70. The cooling channel 73 ends in an outlet 76, by means of which the coolant can leave the cooling channel 73 again in the flow direction RM. In this embodiment of the cooling device 3, the silo receiving unit 72 is first cooled by means of the coolant and then the metered material in the silo 70 is also indirectly cooled.

The first temperature control device may alternatively or additionally comprise, in addition to what is shown here, at least one substantially linear cooling channel, which extends, for example, in the wall of the silo housing unit along the longitudinal extension of the silo (i.e. vertically in this case). If the cooling device comprises a plurality of individual cooling channels, each cooling channel may comprise a separate inlet or outlet opening for the coolant. Alternatively, a plurality of individual cooling channels can be provided with only a common ("central") inlet or outlet opening.

In a further embodiment of the cooling device (not shown), the cooling channel may be configured between the silo wall 71 forming the silo and the inner wall of the silo receiving unit, i.e. in the inner space of the silo receiving unit and thereby annularly enclosing the silo from the outside.

The first tempering device 2 can be used to temper the metered material to a (first) specific (target) temperature substantially in the entire metered material silo 70 as far as into the feed channel 80.

The metering system 1 comprises a second tempering device 2 ', which second tempering device 2' is assigned to the feed channel 80. The inlet passage 80 may, for example, have a substantially circular cross-section. The second tempering device 2 'also comprises a (separately controllable) cooling device 3' and a heating device (not shown). The cooling device 3' comprises a "cooling body" 82, here a cooling channel 82, the cooling channel 82 being arranged in the wall 81 of the inlet channel 80. The cooling channel 82 is helically wound around the entire inlet channel 80. This means that the metered material of the partial section of the feed channel 80, here vertical (connected to the silo 70) and the horizontal partial section connected thereto, in particular in the respective partial section, is in effective contact with the cooling device 3'.

In order to supply the cooling channel 82 with the pre-cooled coolant, the "cooling body" 82 comprises a separately formed inlet 83 (in relation to the inlet 75 of the silo receptacle 72) for the pre-cooled coolant, which inlet is connected to the actual cooling channel 82 by means of a short (horizontal) connecting channel. The cooling channel 82 extends up to a discharge port 84 for discharging coolant from the cooling channel 82.

The second temperature control device can also comprise a plurality of separately designed cooling channels, differing from the one shown here. Each cooling channel may comprise a separate inlet or outlet opening or be coupled by means of only one common ("central") inlet or outlet opening. For example, the cooling channels can also be arranged in the fluid unit at a distance from the supply channel, i.e. in this case the respective cooling channel does not extend directly in the wall of the supply channel.

Alternatively, the individual cooling channels can also be designed such that they surround the inlet channel (when viewed in cross section) from the outside in an annular manner and extend along the course thereof.

The second temperature control device 2' comprises, as described, a heating device (not shown) which is arranged in the frame part 45 of the housing 11 and can be actuated by means of a heating connection cable 87. The metering substance can be tempered to a (second) (nominal) temperature by means of the second tempering device 2' essentially in the entire supply channel 80.

The third temperature control device 2 ″ of the metering system 1 is assigned to the nozzle 40 in order to control the temperature of the metered substance to a (third) (nominal) temperature inside the nozzle 40 in a nozzle chamber 42, the nozzle chamber 42 being directly connected to which the supply channel 80 is. The third temperature-control device 2 "comprises a heating device 4", which is realized here by means of a heating element 85. The heating element 85 may be configured, for example, as an annular heating element 85, in order to delimit the nozzle chamber 42 toward the outside or relative to the housing 11. But the heating element 85 may also be arranged in the housing 11 itself. The third temperature regulating device 2 "may also comprise cooling means 3" (not shown here).

In the embodiment shown here, the respective temperature control device 2, 2', 2 ″ is designed and arranged in the metering system 1 in order to continuously control the temperature of the metered material to the respective specific (setpoint) temperature from the start of the supply, for example from the point in time when the metered material silo 70 is coupled to the housing 11, until the discharge from the nozzle 40. This means that the temperature zones provided for the respective tempering devices 2, 2', 2 ″ are located next to one another. This can be seen in particular in fig. 2.

Fig. 2 shows components of a metering system according to another embodiment of the present invention. The metering system 1 here comprises three temperature zones 6, 6', 6 ″. The first temperature zone 6 is assigned to the metered-substance storage holder 70, wherein the temperature zone 6 completely surrounds the metered-substance storage holder 70. The metered substance storage holder 70 may also be constructed larger than shown here. By means of the temperature control device 2 or the cooling device 3 provided, substantially all of the metered substance in the metered substance storage holder 70 can be controlled in temperature. The cooling device 3 substantially corresponds to that shown in fig. 1 and comprises a cooling channel 73 arranged in the wall of the silo receiving unit 72 and spirally surrounding the silo 70. However, the supply device for the coolant is arranged in the cover region of the silo receiving unit 72 and is connected to the actual cooling channel 73 by means of a short (vertical) connecting channel.

The first temperature zone 6 associated with the metered-substance storage holder 70 directly adjoins the second temperature zone 6' associated with the feed channel 80 in the region of the temperature zone boundary 8. The temperature control device 2 'associated with the second temperature zone 6' is designed to control the temperature of essentially all the metered substances in the feed channel 80. The metered material flows through the input channel 80 in the direction RD.

The second temperature control device 2 'comprises a cooling device 3', the cooling device 3 'corresponding to the configuration of the second (associated with the supply duct) cooling device 3' in fig. 1 and therefore not described here. In this case, however, in contrast to fig. 1, the connection point 83 is connected to an external coolant supply line 97' in order to supply the pre-cooled coolant to the cooling duct 82 in the flow direction RM.

The tempering device 2 ' associated with the second temperature zone 6 ' also comprises a heating device 4 ' having an electrically heated core (Heizpatrone)85, the electrically heated core 85 being arranged above the supply channel 80.

The second temperature zone 6 'adjoins the third temperature zone 6 ″ associated with the nozzle 40 in the region of the further temperature zone boundary 8'. As soon as the metered substance flowing in the direction RD passes this temperature zone boundary 8', i.e. enters the nozzle chamber 42, the metered substance is tempered, for example heated to a processing temperature specific to the metered substance, by means of the third tempering device 2 ″ associated with the nozzle. According to this embodiment of the invention, a continuous "uninterrupted" tempering of the metered substances in the metering system is achieved.

Fig. 3 shows a partial section of a fluidic unit according to another embodiment of the invention. The supply duct 80 is provided with a temperature control device 2 ' having a cooling device 3 ' and a heating device 4 '.

In contrast to fig. 1 and 2, the cooling device 3 'here comprises two separately embodied cooling channels 82', 82 ″ which extend on two opposite sides of the supply channel 80. In the plan view of fig. 3, the first cooling channel 82' runs in the wall 81 on the left or below the supply channel 80 and the second cooling channel 82 ″ runs in the wall 81 on the right or above the supply channel 80. The beginning of the cooling channels may be located in a common input port. In contrast to fig. 1, the cooling channels 82', 82 ″ do not helically surround the supply channel 80, but rather run essentially straight (except for a bend) along the supply channel 80.

The region of the wall 81 of the supply channel 80 (between the two cooling channels 82 ', 82 ″) which is not in direct effective contact with the cooling device 3 ' is at least partially surrounded by the heating device 4 '. The heating device 4 ', in this case a plurality of heating wires 86', is supported directly on the wall 81 from the outside, so that heat can be supplied in a targeted manner to the metered substance in the feed channel 80.

The input channel 80 also comprises four temperature sensors 88' arranged in different areas at the inner side of the wall portion 81. The temperature sensors 88' can deliver the temperature of the metered substance in different regions of the metering system as input parameters for controlling the tempering for the control unit of the metering system (see fig. 6).

In particular, it can be seen in fig. 3 that the temperature control device 2' (and also the remaining temperature control devices of the metering system) is designed to simultaneously cool and heat the metered substances in the respective temperature zones in the temperature control range ("superimposed control").

In fig. 4 a fluid unit according to another embodiment of the invention is shown. In contrast to fig. 3, the temperature control device 2 'associated with the supply duct 80 here comprises a cooling device 3' with only one cooling duct 82 ', the cooling duct 82' (in plan view) extending to the left or below the supply duct 80.

The heating device 4 'of the temperature control device 2' comprises a plurality of individually controllable electric heating cores 85, which are coupled to the control unit by means of individual heating connection cables 87. The electrically heated core 85 is arranged on the one hand in the immediate vicinity of the inlet channel 80 and can, for example, directly adjoin the wall 81 (here in the region of the inlet channel 80). On the other hand, the electrical heating core 85 can also be arranged in the frame part 45 at a distance from the supply channel 80, wherein the cooling channel 82' can extend between the electrical heating core 85 and the supply channel 80.

Fig. 5 shows a fluidic unit according to another embodiment of the present invention. In contrast to fig. 1 to 4, the cooling device 3' does not comprise a flowing precooled cooling fluid here, but instead comprises a stationary cooling source, in this case a peltier element 99, which is integrated into the fluid unit 30. The peltier elements 99 are arranged here directly in the wall 81 of the feed channel 80. For controlling the cooling power, the peltier element 99 can be actuated by a control unit by means of the connection cable 89.

The peltier element 99 can be used on the one hand to actively cool the metered substance in the feed channel 80. On the other hand, however, the same peltier element 99 can also be used for heating the metered substance in the inlet channel 80. The current in the peltier element 99 causes (actively) cooling of one region or side of the peltier element 99 while heating of the opposite side of the peltier element 99. Whereby peltier elements 99 form a cold side and a hot side.

The direction of the current flowing through the peltier element 99 may be selected as desired to cool or heat a side of the peltier element 99, for example, a side facing the input channel 80. The metered substance in the feed channel 80 can thus be cooled or heated as desired by means of only one peltier element 99. The peltier element 99 can be operated as a cooling source or as a heating device. A separate heating device can therefore in principle be dispensed with due to the different operating types of the peltier element 99.

In order to cool the metering substance particularly effectively by means of the peltier element 99, the peltier element 99 can preferably be arranged in the fluid unit 30 in such a way that the heat generated during operation of the peltier element 99 can be removed from the peltier element 99 as efficiently as possible. In this case, the "heat-generating" side of the peltier element 99 (the side facing away from the supply duct 80) can be flowed through from outside the metering system, for example with compressed room air.

Despite the different operating modes of the peltier element 99, the temperature control device 2' here comprises a separate electrical heating core 85, the electrical heating core 85 being arranged (in a plan view looking at the inlet channel 80) on the side of the inlet channel 80 opposite the peltier element 99. The two "temperature control elements" 85, 99 are arranged "offset" in relation to the flow direction RD of the metered substance in the supply channel 80. The situation shown in fig. 5 may be such that the inlet channel 80 is directed towards the nozzle in a region shortly before the inlet of the inlet channel 80. By means of the peltier element 99, for example, the metered substance can be cooled down to a defined region of the feed channel 80, for example to the right end of the peltier element 99.

Since the metered substance (not shown) in the nozzle is usually heated to the process temperature, it is advantageous if the cooling of the metered substance is terminated in the region of the feed channel 80 shortly before the nozzle and is instead started with a "pre-conditioning" of the metered substance, for example by means of an electrical heating core 85. The tempering device 2' can thus be configured as shown here such that only the metered substance is cooled in a first sub-zone of the temperature zone, wherein the metered substance is heated purely in a second sub-zone of the temperature zone, in which the latter is located "downstream" here.

Fig. 6 schematically shows the configuration of the tempering system 7 according to an embodiment of the metering system.

The control unit 50 controls a refrigeration source 95, for example a compression refrigerator 95, in dependence on at least one input parameter of the metering system 1 such that the coolant is cooled to a specific (first) temperature. The refrigerant, for example compressed room air, is supplied to the refrigerator 95 by means of the compressed air supply 90. The coolant discharged from the compression refrigerator 95 has been cooled to a temperature below the ambient temperature of the metering system 1 and reaches the two (parallel) downstream vortex tubes 93, 93' by means of suitable isolating lines.

The two vortex tubes 93, 93' are designed to cool the pre-conditioned coolant to a final (target) temperature in a targeted manner. The two vortex tubes 93, 93' can be actuated individually by means of the control unit 50 in order to cool the coolant to different (nominal) temperatures.

In order to adjust the cooling power, each of the two vortex tubes 93, 93 ' comprises a controllable regulating valve 94, 94 ' in the region of the hot air outlet HAW of the respective vortex tube 93, 93 '. The temperature and the (volume) flow of the cooled coolant (cooling air portion) can be regulated by means of the valves 94, 94'. In principle, the opening of the valves 94, 94 'reduces the flow rate and the temperature of the cooling air flowing out of the respective vortex tube 93, 93'. The cooled coolant leaves the vortex tubes 93, 93 'in the direction RM at the cold air outlet of the vortex tubes 93, 93'. The "hot air portion" of the vortex tubes 93, 93 'is led away from the vortex tubes 93, 93' by means of the respective hot air outlet HAWs. In order to set the respective volumetric flow of coolant into the vortex tubes 93, 93 ', the respective vortex tube 93, 93 ' can be preceded by a separate proportional valve 92, 92 ', which can be actuated by means of the control unit 50.

In the embodiment of the tempering system 7 shown here, the pre-cooled coolant of the first (here the left-hand) vortex tube 93 is used to temper the temperature region associated with the dosing material silo 70. The coolant reaches the cooling channel 73 by means of a coolant input line 97 to cool the metered material in the silo 70, which is coupled at one end to the vortex tube 93 and at the other end to the coolant input line 97 of the silo housing unit 72. The coolant leaves the cooling channel 73 in the region of the hot air outlet HAD of the metering system by means of a coolant outlet line 98. A controllable pressure reducer 96 is optionally provided between the vortex tube 93 and the cooling channel 73.

The coolant flowing out of the second (here the right) vortex tube 93' is used for tempering the temperature zones provided for the inlet channels (not shown) of the fluid unit 30. The coolant reaches the cooling channel 82 by means of a separate coolant feed line 97' to cool the metered material in the feed channel. An optional pressure reducer 96 'is also provided here between the vortex tube 93' and the cooling channel 82. Owing to the (second) vortex tube 93' which can be operated separately, the metered substance in the feed channel can be tempered to a different, preferably higher (nominal) temperature than the metered substance in the silo 70. The coolant leaves the cooling channels 82 by means of a separate coolant discharge line 98'.

In fig. 6, the refrigerant compressor installation 95 cooperates with the two cooling devices 3, 3' of the metering system 1. The respective cooling device 3, 3 'in the case shown here achieves cooling of the metered material in the silo 70 or in the feed channel by means of separate partial cooling circuits 3, 3', which are each individually coupled to the refrigeration compressor installation 95. This means that the cooling device 3 provided for the metered-substance storage holder 70 and the cooling device 3' provided for the inlet channel jointly use the refrigerant supplied by the refrigerant compression device 95.

The cooling device 3 associated with the metered-substance storage holder 70 also comprises a separate vortex tube 93 in addition to the cooling channel 73, the connection point for the coolant supply line 97 and such a supply 97. Furthermore, part of the cooling circuit 3 is coupled to the refrigeration compression device 95 as described so as to use the supplied refrigerant. Correspondingly, the cooling device 3 ' associated with the supply channel also comprises the cooling channel 82, a connection point with a coolant supply line 97 ' and its own vortex tube 93 ' and is likewise (separately) connected to the refrigerant compressor device 95.

In order to be able to operate the two partial cooling circuits 3, 3 'separately, i.e. in order to be able to determine the cooling of the respective temperature zone separately, the volume flow of the coolant in the respective partial cooling circuit 3, 3' can be controlled by the control unit 50 by means of the respective proportional valve 92, 92 'and/or the temperature of the coolant in the respective partial cooling circuit 3, 3' can be controlled by means of the regulating valve 94, 94 'of the respective vortex tube 93, 93'. In the exemplary embodiment shown here, each of the two cooling devices 3, 3 'comprises two different cooling sources 55, 93 or 55, 93'. The present invention therefore relates to a multi-part refrigeration source.

In order to achieve a temperature control of the respective temperature region which is as stable as possible, in particular which is not susceptible to interference, the temperature control device 2 associated with the metered-substance storage holder 70 and the temperature control device 2 ' associated with the feed channel each comprise a separate heating device 4, 4 ', which is realized here by means of a corresponding heating wire 86, 86 '. The temperature of the metered substances in the silo 70 and/or in the feed channel is regulated by means of the principle of "superimposed regulation" as a function of the actuation by the control unit 50.

The tempering device 2 "associated with the nozzle 40 also comprises a heating device 4", here in the form of a heating wire 86 ", for heating the metered substance in the nozzle 40 to the process temperature. The individual heating devices 4, 4 ', 4 "of the different temperature control devices 2, 2', 2" can be controlled individually by the control unit 50 by means of heating connection cables 87.

The metering system 1 also includes a plurality of temperature sensors 88, 88' to detect the temperature of the metered material in the silo 70 and in the input channel. A plurality of temperature sensors may also be provided for the nozzle 40 or the nozzle chamber, different from that shown here. The corresponding measurement data are fed as input variables individually to the control unit 50 by means of the temperature sensor connection cable 52.

The control unit 50 calculates or carries out a temperature management of the metering system as a function of the input parameters or other input parameters in order to adjust the temperature of the metered substances in the different temperature zones as advantageously as possible. For this purpose, the control unit 50 can apply corresponding control signals to the refrigerant compressor device 95, the respective proportional valve 92, 92 ', the respective vortex tube 93, 93 ' or the regulating valve 94, 94 ', the respective pressure reducer 96, 96 ', the respective heating device 4, 4 ', 4 ″ and, if appropriate, further components.

The aforementioned regulating elements, i.e. the controllable compression refrigerator 55, the proportional valves 92, 92 ', the pressure reducers 96, 96 ', and the controllable regulating valves 94, 94 ' can be used individually or in addition. The illustrated arrangement of the principal temperature control system 7 therefore shows an approximately maximum structural hierarchy in order to describe the function of the individual components.

Finally, it is again pointed out that the metering system described in detail above is merely an embodiment which can be modified in different ways by the skilled person without leaving the scope of the invention. Thus, for example, a single cooling device may also comprise a plurality of vortex tubes. The use of the indefinite article "a" does not exclude the case that a plurality of features is also present.

List of reference numerals

1 metering system

2. 2 ', 2' temperature regulating device

3. 3 ', 3' cooling device

4. 4 ', 4' heating device

5 metering device

6. 6 ', 6' temperature zone

7 temperature adjusting system

8. 8' temperature zone boundary

10 actuator unit

11 casing

11a (first) housing part

11b (second) housing part

12 actuator chamber

13 action chamber

14 movement mechanism

15 gap

16 lever

17 contact surface of lever

18-lever bearing

19 actuator spring

20 pressing piece

21 input port/actuator Chamber

22 vent/actuator chamber

23 fastening screw

30 fluid unit

31 tappet

32 tappet tip

33 tappet head

34 contact surface of tappet

35 Tappet spring

36 Tappet seal

37 tappet bearing

40 nozzle

41 nozzle orifice

42 nozzle chamber

43 sealing seat

44 coupling site/housing

45 frame component

50 control unit

51 control cable

52 temperature sensor connecting cable

60 piezoelectric actuator

61 contact pin

62 actuator control connection

70 metering material silo

71 silo wall section

72 silo accommodation unit

73 cooling channel/silo

74 walls of silo housing unit

75 input port/silo

76 discharge outlet/silo

77 coupling site/silo

80 input channel

81 wall of an input channel

82. 82 ', 82' Cooling/feed channel

83 input ports/input channels

84 discharge port/discharge channel

85 electric heating core (Heizpatrone)

86. 86 ', 86' electric heating wire

87 heating connection cable

88. 88' temperature sensor

89 Peltier element connecting cable

90 compressed air input

92. 92' proportional valve

93. 93' vortex tube

94. 94' vortex tube valve

95 refrigerating compressor

96. 96' pressure reducer

97. 97' Coolant inlet line

98. 98' coolant discharge line

99 Peltier element

Hot air output part of HAW vortex tube

Hot air output part of HAD metering system

K inclined axis

R direction of injection

RD measures the flow direction of a substance

RM coolant flow direction.

Claims (15)

1. A metering system (1) for metering a substance, having a metering device (5) comprising a housing (11) and a metered substance storage holder (70) coupled to the housing (11) or integrated in the housing (11), wherein the housing (11) has an inlet channel (80) for the metered substance, a nozzle (40), a spray element (31) and an actuator unit (10) coupled to the spray element (31) and/or the nozzle (40), wherein,

the metering system (1) has a plurality of temperature control devices (2, 2 ') which are each associated with a different temperature zone (6, 6 ') of the metering system (1) in order to control the temperature zones (6, 6 ') differently,

-providing at least one first temperature zone (6) to the metered substance storage holder (70) and at least one second temperature zone (6 ") to the nozzle (40), and

preferably, at least one of the tempering devices (2, 2 ', 2 "), preferably at least the tempering device (2) provided for the metered-substance storage holder (70), comprises a cooling device (3, 3 ', 3") having at least one cooling source (93, 93 ', 95, 99).

2. The metering system according to claim 1, wherein the cooling source (95) of the cooling device (3, 3 ', 3 ") is configured to cool the coolant of the cooling device (3, 3', 3") to a presettable temperature and/or wherein the cooling source (93, 93 ') comprises at least one vortex tube (93, 93').

3. Metering system according to claim 1 or 2, having a control unit (50) and/or a regulating unit (50) to control and/or regulate the tempering device (2, 2 ', 2 "), preferably in order to temper the metered substance in the respective temperature zone (6, 6', 6") to a nominal temperature.

4. Metering system according to one of claims 1 to 3, wherein the tempering device (2, 2 ', 2 "), preferably at least the tempering device (2") with which the nozzle (40) is equipped, comprises a heating device (4, 4', 4 ").

5. Metering system according to claim 4, wherein the tempering device (2, 2 ', 2 ") is equipped with a control unit (50) and/or a regulating unit (50) configured to individually control and/or regulate the cooling means (3, 3', 3") and the heating means (4, 4 ', 4 ") of the tempering device (2, 2', 2").

6. Metering system according to one of claims 3 to 5, wherein the control unit (50) and/or regulating unit (50) is configured to control and/or regulate a tempering device (2, 2', 2 ") for tempering a metered substance as a function of at least one input parameter, preferably a volume flow and/or a temperature and/or a viscosity.

7. The metering system as claimed in claim 6, wherein the tempering device (2, 2 ', 2 ") is equipped with at least one temperature sensor (88, 88') for generating the input parameter in the metering system (1).

8. The metering system according to any one of claims 4 to 7, wherein the cooling device (3, 3 ', 3 ") and the heating device (4, 4 ', 4") of the tempering device (2, 2 ', 2 ") are constructed separately, in particular spatially separated from one another.

9. The metering system as claimed in any of the preceding claims, wherein the metering system (1) comprises at least one further tempering device (2 '), the further tempering device (2') being assigned to a third temperature zone (6 '), the third temperature zone (6') being assigned to an input channel (80) of the metering system (1).

10. The metering system of any one of the preceding claims, wherein the metered substance storage holder (70) comprises a metered substance storage container (70).

11. Method for operating a metering system (1) for metering a metered substance, having a metering device (5) comprising a housing (11) and a metered substance storage holder (70) coupled to the housing (11) or integrated in the housing (11), the housing comprising an inlet channel (80) for the metered substance, a nozzle (40), a spray element (31) and an actuator unit (10) coupled to the spray element (31) and/or the nozzle (40), wherein,

-differently tempering a plurality of temperature zones (6, 6 ') of the metering system (1) by means of a plurality of tempering devices (2, 2 ') of the metering system (1), which are respectively assigned to different temperature zones (6, 6 '),

-tempering at least one first temperature zone (6) assigned to the metered-substance storage holder (70) differently from at least one second temperature zone (6') assigned to the nozzle (40), and

-tempering at least one of the temperature zones (6, 6 ', 6 "), preferably at least the temperature zone (6) provided for the metered-substance storage holder (70), by means of a cooling device (3, 3 ', 3") provided to the tempering device (2, 2 ', 2 "), preferably.

12. Method for operating a metering system according to claim 11, wherein a temperature zone (6 ") associated with the nozzle (40) is tempered such that the temperature of the metered substance in this temperature zone (6") corresponds to the metered substance processing temperature.

13. Method for operating a metering system according to claim 11 or 12, wherein the temperature zone (6) provided for the metered substance storage holder (70) is tempered such that the temperature of the metered substance in this temperature zone (6) is lower than the temperature of the metered substance in the temperature zone (6 ") provided for the nozzle (40) and/or lower than the ambient temperature of the metering system (1), wherein preferably the temperature of the metered substance in the respective temperature zone (6, 6', 6") is determined depending on an expected or actual metered substance throughput.

14. Method for operating a metering system according to one of claims 11 to 13, wherein a temperature zone (6 ') associated with the feed channel (80) of the metering system (1) is tempered in such a way that the temperature of the metered substance in this temperature zone (6') is higher than the temperature of the metered substance in the temperature zone (6) associated with the metered substance reservoir holder (70) and/or lower than the temperature of the metered substance in the temperature zone (6 ") associated with the nozzle (40).

15. Method for operating a metering system according to one of claims 11 to 14, wherein the cooling means (3, 3 ', 3 ") and the heating means (4, 4 ', 4") of the tempering device (2, 2 ', 2 ") are controlled and/or regulated separately to temper the metered substance to a nominal temperature.

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